Over the past 10-15 years, there has been a convergence of neuroscience, engineering and the increasing availability of fast and inexpensive computer processing, which has led to the emergence of the field of motor neuroprosthetics as a practical reality for people with severe motor disability. A motor neuroprosthetic device, also known as a Brain Computer Interface, or BCI, is a device that can monitor and decode the electrical language of the user's thoughts and convert that information into some type of overt machine control (e.g., controlling a cursor on a screen or moving a robotic arm). Recent experiments over the past 5 years have produced impressive demonstrations in animal and human subjects in which overt computer control has been accomplished with brain signals alone. This type of technology holds immense promise for people with such diseases as spinal cord injury, stroke and neuromuscular disorders. It may allow disabled individuals to more substantially and meaningfully communicate and interact with their environments.

In the past 5 years, it has emerged as a practical clinical alternative to more classic methods of single neuron- and electroencephalographic (EEG)-based systems. ECoG is a very promising intermediate BCI modality because it has higher spatial resolution, better signal-to-noise ratio, wider frequency range, and fewer training requirements than scalp-recorded EEG, and at the same time has lower technical difficulty, lower clinical risk, and probably superior long-term stability than intracortical single-neuron recording. The notable advantages of ECoG as a neuroprosthetic platform also provide superior spatial and temporal resolution in understanding human cortical physiology. This has allowed for an advanced understanding of human cognition and motor processing beyond classic motor intentions. Recent findings in ipsilateral premotor regions, prefrontal areas and language cortex demonstrate additional neuronal networks and features that may be amenable for utilization for a highly functional Brain Computer Interface (BCI) in the future.

PodcastEric Leuthardt, MD, director of the Center for Innovation in Neuroscience and Technology, is interviewed on the “Evolution of Brain Computer Interfaces” for a podcast produced by the journal Neurosurgical Focus.

BCI control of the video game Space Invaders

The patient is controlling his cannon by using both real and imagined hand and tongue movements. The signals are recorded from the surface of his brain, known as electrocorticography (ECoG), and the cortical changes that are associated with his motor intentions are detected by a computer and converted to machine commands (i.e., moving the shooting cannon).